From 0f6ddc3871fb6e5ae617468af75062c9d3ac2b35 Mon Sep 17 00:00:00 2001
From: v3xro <175618876+v3xro@users.noreply.github.com>
Date: Tue, 30 Jul 2024 17:53:33 +0100
Subject: [PATCH 1/3] fix(bind): allow serialization of Some(_) and None values
 (as the inner value and NULL respectively)

---
 src/sql/ser.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/sql/ser.rs b/src/sql/ser.rs
index 3120f9e..dbea2b0 100644
--- a/src/sql/ser.rs
+++ b/src/sql/ser.rs
@@ -86,7 +86,6 @@ impl<'a, W: Write> Serializer for SqlSerializer<'a, W> {
     unsupported!(
         serialize_map(Option<usize>) -> Result<Impossible>,
         serialize_bytes(&[u8]),
-        serialize_none,
         serialize_unit,
         serialize_unit_struct(&'static str),
     );
@@ -141,7 +140,13 @@ impl<'a, W: Write> Serializer for SqlSerializer<'a, W> {
 
     #[inline]
     fn serialize_some<T: Serialize + ?Sized>(self, _value: &T) -> Result {
-        Err(SqlSerializerError::Unsupported("serialize_some"))
+        _value.serialize(self)
+    }
+
+    #[inline]
+    fn serialize_none(self) -> std::result::Result<Self::Ok, Self::Error> {
+        self.writer.write_str("NULL")?;
+        Ok(())
     }
 
     #[inline]

From 97b925e918d9eb6c151a4f2c089ca827e96303b3 Mon Sep 17 00:00:00 2001
From: v3xro <175618876+v3xro@users.noreply.github.com>
Date: Wed, 31 Jul 2024 12:36:34 +0100
Subject: [PATCH 2/3] chore: add tests

---
 src/sql/mod.rs | 21 ++++++++++++++-------
 src/sql/ser.rs |  4 ++--
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/src/sql/mod.rs b/src/sql/mod.rs
index 76ab3ef..edb42e7 100644
--- a/src/sql/mod.rs
+++ b/src/sql/mod.rs
@@ -184,6 +184,20 @@ mod tests {
         );
     }
 
+    #[test]
+    fn option_as_null() {
+        let mut sql = SqlBuilder::new("SELECT 1 FROM test WHERE a = ?");
+        sql.bind_arg(None::<u32>);
+        assert_eq!(sql.finish().unwrap(), r"SELECT 1 FROM test WHERE a = NULL");
+    }
+
+    #[test]
+    fn option_as_value() {
+        let mut sql = SqlBuilder::new("SELECT 1 FROM test WHERE a = ?");
+        sql.bind_arg(Some(1u32));
+        assert_eq!(sql.finish().unwrap(), r"SELECT 1 FROM test WHERE a = 1");
+    }
+
     #[test]
     fn failures() {
         let mut sql = SqlBuilder::new("SELECT 1");
@@ -191,13 +205,6 @@ mod tests {
         let err = sql.finish().unwrap_err();
         assert!(err.to_string().contains("all arguments are already bound"));
 
-        let mut sql = SqlBuilder::new("SELECT ?");
-        sql.bind_arg(None::<u32>);
-        let err = sql.finish().unwrap_err();
-        assert!(err
-            .to_string()
-            .contains("invalid argument: serialize_none is unsupported"));
-
         let mut sql = SqlBuilder::new("SELECT ?fields");
         sql.bind_fields::<Unnamed>();
         let err = sql.finish().unwrap_err();
diff --git a/src/sql/ser.rs b/src/sql/ser.rs
index dbea2b0..5ab55d9 100644
--- a/src/sql/ser.rs
+++ b/src/sql/ser.rs
@@ -345,8 +345,8 @@ mod tests {
     fn it_fails_on_unsupported() {
         let mut out = String::new();
         assert!(write_arg(&mut out, &std::collections::HashMap::<u32, u32>::new()).is_err());
-        assert!(write_arg(&mut out, &None::<u32>).is_err());
-        assert!(write_arg(&mut out, &Some(42)).is_err());
+        assert!(write_arg(&mut out, &None::<u32>).is_ok());
+        assert!(write_arg(&mut out, &Some(42)).is_ok());
         assert!(write_arg(&mut out, &()).is_err());
 
         #[derive(Serialize)]

From f515d3be523140bb87435a3e7238d511ebeec214 Mon Sep 17 00:00:00 2001
From: v3xro <175618876+v3xro@users.noreply.github.com>
Date: Mon, 5 Aug 2024 20:35:44 +0100
Subject: [PATCH 3/3] chore: move test for option into own function

---
 src/sql/ser.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/sql/ser.rs b/src/sql/ser.rs
index 5ab55d9..00ea606 100644
--- a/src/sql/ser.rs
+++ b/src/sql/ser.rs
@@ -341,12 +341,17 @@ mod tests {
         assert_eq!(check((42, 43)), "(42,43)");
     }
 
+    #[test]
+    fn it_writes_options() {
+        assert_eq!(check(None::<i32>), "NULL");
+        assert_eq!(check(Some(32)), "32");
+        assert_eq!(check(Some(vec![42, 43])), "[42,43]");
+    }
+
     #[test]
     fn it_fails_on_unsupported() {
         let mut out = String::new();
         assert!(write_arg(&mut out, &std::collections::HashMap::<u32, u32>::new()).is_err());
-        assert!(write_arg(&mut out, &None::<u32>).is_ok());
-        assert!(write_arg(&mut out, &Some(42)).is_ok());
         assert!(write_arg(&mut out, &()).is_err());
 
         #[derive(Serialize)]